DNA replication is the process by which a double-stranded DNA molecule is copied to produce two identical DNA molecules.
The heart pumps oxygenated blood to the body and deoxygenated blood to the lungs. In the human heart there is one atrium and one ventricle for each circulation, and with both a systemic and a pulmonary circulation there are four chambers in total: left atrium, left ventricle, right atrium and right ventricle.
pulmonary circulation. The flow of blood from the right ventricle of the heart to the lungs for exchange of oxygen and carbon dioxide in the pulmonary capillaries, then through the pulmonary veins to the left atrium. See: illustration. See also: circulation.